We once referred to vintage Jeep 4x4s as the most modified and cannibalized vehicles on the planet. Beginning with WWII surplus MB Willys Jeep models, most off-road rigs got a good dose of upgrades, from oversized tires to V-8 conversions.

So popular was the modification approach that in the Chrysler/Jeep Mopar era, we refer to the Jeep as the most "personalized" vehicle around, with catalogs full of accessories, chassis upgrades and winches.

Today, for the first time, vintage Jeep vehicles have shown a bump in value, even finding their way to Mecum and other auctions alongside vintage collectible cars and nostalgia muscle cars. With that trend, for the first time, a vintage Jeep is judged for its originality and an authentic restoration.

So, we're at a crossroads. What do you think about modifying a 1941-86 Jeep 4x4 for extreme trail use? Or are you considering a bolt-by-bolt restoration of a vintage Model MB, CJ-3B, an M38AI, FC150, FC170, Willys Pickup or Willys Station Wagon?

My build of a 1985 Jeep CJ-7 is strongly influenced by the methods written in the Jeep Owners Bible by Moses Ludel. I think the author's intent is to respect and maintain the OEM's researched design and engineering while incorporating superior aftermarket parts that fit in with the original design and vehicle purpose. For example, while the book addresses considerations of drastically raising the suspension with lift springs, such as a Drop Pitman arm and changing driveline angles, the actual built vehicle is kept close to OEM specs with 2.5" lift springs. I like this practical appoach as I want a daily driver as well as on/off-road multi-purpose utility vehicle from my Jeep. I would not call this vehicle build approach "auto-restoration". I see auto-restoration as an obsessive-compulsive's hobby or a business for the very talented.

Hi, Manny, welcome to the forums! Your comments brought back a cascade of memories. My original intent when drafting the Jeep Owner's Bible stemmed from several principles. My driving background included high stakes, remote areas of northern Nevada, with seasons ranging from winter sub-zero extremes to summer days that taxed a vintage Jeep's cooling system to the limit. I "lived Jeep" from my learner's permit through my first driver's license exam, followed by years of high desert exploration and hunting seasons in shale above timberline. By the time I first did the Rubicon Trail in a stone-stock '64 CJ-5 Jeep (1967), I was an 18-year-old veteran four-wheeler.

Within a year of that trip, my professional automotive technical career began with several years of work as a light and medium duty truck fleet mechanic, an environment where preventive care and OEM integrity ruled. Later, this penchant for bringing vehicles back to original equipment standards got further reinforced by an apprenticeship with the Operating Engineers Union, where a journeyman repairman/welder was responsible for off-highway equipment and machinery that would today be worth $200K to $1M or more per piece. I continued to four-wheel in primitive, remote country during my off time, working jobs like the I-80 bypass of Winnemucca, Nevada.

All of that carried into my career as an automotive journalist and author, and the primary aim with the Jeep Owner's Bible and my subsequent Bentley books was to convey "how to think like a professional mechanic and experienced four-wheeler". In my view and experience, that mechanic was a fleet truck and off-highway equipment professional bent on preventive maintenance and OEM-class repairs. My goal has always been to prevent a vehicle breakdown or failure in service...Which has also made sense for my Jeep and other off-pavement, backcountry use 4x4s.

Today, trails like the Rubicon and vehicles like the 116" wheelbase Jeep JK Wrangler four-door 4x4 require 35" or larger diameter tires. This is in part due to the horrendous deterioration of these trails from theme park traffic numbers, and partly due to wheelbase lengths that rival traditional 1/2-ton, full-size pickup trucks. When I wrote the first edition of the Jeep Owner's Bible, released over twenty years ago, it was sensible to say that 33" tires were the largest diameter needed on any Jeep utility 4x4 of that era.

I still subscribe to 31"-33" tires for a Jeep 94" wheelbase CJ-7, and as you hint, Manny, that eliminates the laundry list of "trickledown" effects and required modifications needed to support 35" and bigger tires. I have always been concerned about center-of-gravity and roll center for the vintage Jeep 4x4s—they have relatively narrow track widths. Since first publishing in the early '80s, I have recommended the use of wider, negative offset wheels to widen the track width on lifted 4x4 vehicles.

From a pragmatic use and resale value standpoint, the moderate changes described in my books reflect a restorative philosophy. This stems from years at truck fleet and equipment maintenance work. If your four-wheeling is on reasonable trails and not full-on rock crawling, 31" to 33" tire diameter would work fine, requiring a 2.5" to 4" lift on your Jeep CJ-7. The vehicle could easily be restored to stock if necessary, as the modifications for fitting these tires would be minimal.

4x4 modifications have a lot to do with driving environments, outdoor interests and concern for environmental impact. My past years as the Media Representative on the Tread Lightly, Inc., Board of Directors further reinforced a longstanding respect for the environment—and our shared responsibility as backcountry land users.

Thanks for joining us, Manny, I look forward to your contribution and discussions at the forums—members and guests would enjoy photos of your CJ-7 at the new forums photo gallery! We'd like to hear about your four-wheeling interests, too!

I have to say that I hate to see an unmodified flattie get changed. I love to modify my CJs but uncut, stock originals are hard to find. The combination of being beat to death on farms or other industrial use removed many from circulation. The ease with which they are modified took a huge percentage away from stock. Plus, sadly, for as tough as they were, they are really very flimsy as far as rust. (The rust problem lasted all the way through the end of the CJ and beyond.)

I kinda agonized with my current 85 CJ-7. I bought it from the original owner, zero rust and stone stock. Restoring it was my first thought, but my urge to figure things out and modify them won out.

I recently saw a TV show (can't remember which one) where somebody had saved a couple 86 CJ-7s straight off the dealers lot, including one that had never even been registered yet. No way anybody can say those aren't collectible and need to be preserved as is.

This is really a kind of thought provoking topic...is a 62 Tuxedo Park CJ-5 as collectible as a 69 Z-28? Obviously not, but they made a lot less of them and there are certainly very few of them left now, so who is to say?

My personal favorites: Willys MB Slat Grill, CJ-2A, M-38 (not A1), Kaiser era CJ-5 w/ V6 and pre-ugly (73?) Commando, any year Forward Control. And of course the 80-86 CJs, even though they had so screwed up the transmissions options by then (SR-4...really?)

Sorry Moses I have to disagree with the CJ-3B, I just want to take a baseball bat and knock that hood back down where it belongs!

The Willy's will have the '74 drivetrain but everything else as original as I can. I only have the T90 and Tcase. I do want to put the skinny tires on it and wait for some kid to pull up at a light and then smoke the tires-hahaha.

My CJ8-they only made something like 27K and there are many missing/gons to it is rarer than many models out there. The other Cj's are staying some what stock but I keep all the original parts for my great grand kids (that is if my kids ever get married).

I don't think I will do any body work, it's clean, but has some bumps and bruises and that's cool

As Mopar likes to say, "Jeep is the most personalized vehicle in the World!" As for collectibles, there have been recent auction hints of purest restorations bringing value to a Jeep, and that's a plus. For years, the "value" was in the modifications and add-on components.

Worth noting is that the Jeep models from their inception (MB) were the most cannibalized and parts mixed of any vehicle. This is largely due to their utility and continued worth as running "machines" or beasts of burden. I recall Arthur Warn's conversion kit to strip a WWII MB surplus vehicle to two-wheel drive for economy and ease of service! Eventually, his removable hub kit won out as a way to preserve 4WD yet have a bit less frictional loss and wear on the front drive system. With a side-driving Model 18 Spicer transfer case, good luck there...

We're all in accord that some Jeep models are best left alone, generally very low production types or extraordinarily low mileage examples that are stone stock. A case in point, "ssgtandy" (Chad) just joined us and has found a 1991 Grand Wagoneer. If such a vehicle is in pristine, original equipment mode, I would keep it that way and be very faithful about OEM replacement parts and a restoration mindset...

As for the CJ-3B's high hood, I can lose the F-head four any time, but there's ample room for a nice V-6 Buick there...

High hoods are actually cool, I think Mahindra may even still be making them.

My previous Jeep was an 81 CJ-8, and I have never regretted selling a vehicle as much. I did resto-mod it. Also a TBI V8, 305 in this case. Also an NV4500 (Dodge version on this one). I would have kept it stock if it were a 258 / T-176 combination, but sadly is was an "Iron Duke / SR-4". I'll give the Iron Duke one thing, its pretty robust. Mine leaked so bad I once ran it out of oil to the point that the lifters started banging. Serviced it and it ran again. Now the SR-4...no up side to that thing.

Wow, a trip down Memory Lane! Recall the 'Project Trials Machine' 1983 CJ-5 I did for OFF-ROAD in the 1990-91 era? It, too, was originally plagued by the Iron Duke and SR4, both of which vanished with a retrofit 4.2L inline six and NP435 4-speed upgrade...That Jeep CJ was a feature in my first and subsequent editions of the Jeep Owner's Bible.

The real memory jog is your comment about the oil leaking main seals. I worked at a GMC Truck/Pontiac dealership as a line mechanic when the Iron Duke was a Pontiac and S-truck mainstay. That pushrod 2.5L was robust enough and had a rugged intrinsic design; however, G.M. could not get an OEM rear main seal to work and used a rope type replacement seal from the Stone Age as a warranty fix. Early S10 trucks and G.M. passenger cars flooded the dealerships, both within and out of warranty.

I recall pulling rope main seals into position under warranty, much like working on a Stovebolt Chevy six or vintage GMC Jimmy six. Replacement with a lip type seal from that era was a total loss, as the oil retention slits on the crankshaft surface puked oil past the lip seal. (The rope seals wept oil at a lesser pace, until they got chewed up nicely by the slit surfaces!) G.M. had similar issues with the 2.8L/173 60-degree V-6, and we did our share of S/T truck main seals, too. I was unlucky enough to do this warranty work stint during the 1983-84 model years, which preceded the use of one-piece main seals and a bigger journal crankshaft on the 2.8L V-6. 1984-86 Jeep XJ Cherokee owners knew all about the 2.8L V-6 rear main seal leaks...and breaking crankshafts.

Both of these engines, borrowed from G.M. by AMC for light Jeep models, reinvented themselves with newer rear main seal designs during the mid-'80s. The redesigned 2.8L/3.1L V-6 and rugged 151 and 181 (marine use) inline pushrod Iron Duke four-bangers lived on for years.

I ended up with a '49 CJ2A in a trade with my son last year. Not my first Willys, I've owned three '57 Wagons and a 78 CJ7 in the past, as well as two XJ's, one of which I'm using in the hills around my home here in Idaho. The 49 2A came to me halfway through an engine conversion that has a 2300 Ford mounted ahead of the original transmission and case. Temporary engine mounts at this time, no exhaust, fuel supply, cooling system, just the engine sitting between the rails on some adjustable mounts till the final mounts are fabbed. I got a disassembled F head 134 with this outfit, and the hood has had a really funky 'hump' welded on to accommodate the carb and air cleaner when the F head was in there. BTW, I understand that this outfit was purchased originally for one of the city golf courses new, and was modified over the years with the F head, and finally the Ford before the last owner sold it off. Not much of the ineterior left, it had import sedan seats mounted inside, and those came out with a good tug! There's a home made rollbar that may stay after I check the welds and maybe add some buttresses.

I believe that I'll finish up the 2300 Ford swap, convert to twelve volt system throughout, and seriously look into disc brake and Saginaw steering upgrades before venturing very far from home. Speed limit in any direction from home does not exceed 65, and probably 98 percent of the roads and trails are gravel, or perhaps at best oiled gravel. More than anything, I see this outfit being hauled out behind the pickup/camper, and used from there to explore the old trails and hunt and fish from. We thought about getting 'four wheelers', but my physical condition won't let me ride one of those 'bronc's.....

A friend of mine in Michigan called the other day, and asked if I'd like to come visit, and take home his '47 CJ2A! That one is original, with a complete extra drivetrain included. Mike bought this one back in the late 60's when he was in high school, and drove it till he finished college and got married. Got a trailer. Got a pickup that'll pull the load. All I have to do is pony up the bucks for gas and grub for a 3500 mile trip at 10 mpg in the Super Duty! I believe that Mike's Willys will see a frame off restoration, the 49, well, it'll see mods, and I'm fine with that.

One thing, though........for all the fun that those old 'flatties' are, I still really, really like driving around in the 98 XJ, with a roof, windows, air, a heater, defroster, radio.........perhaps one day, I'll think about modifying the Cherokee, but not for now!

Welcome to the forums, Rocket Doctor! I'm delighted to see your depth of Jeep immersion. I followed your post with earnest and could identify with your Jeep "process" and conclusions...You will have the best of both CJ2A worlds with the stock/restored '47 and a '49 with light and sensible performance and safety upgrades.

I recall the original popularity of 2.3L Pinto engines as flat fender transplants, the first one I saw was in a closed course race. I'm even old enough to remember slant four 195 Pontiac Tempest transplants that screamed in lightweight vintage Willys/Jeep CJ 4x4s, one comes to mind that won very steep Western Nevada hill climb competitions in the early '70s. Mickey Thompson popularized Pontiac V-8s and ran a dragster with a highly modified slant four—which was actually half of a 389 Pontiac V-8 and, much to G.M.'s credit, slanted away from left hand drive steering boxes. I-H took a similar tack with the early Scout 152 and 196 slant fours, cut from the 304 and 392 I-H V-8s, respectively.

Trusting you'll raise the funding for the 10 mpg trip to Michigan, the '47 sounds very original and worthwhile for a stock restoration. The '49 deserves disc brakes and Saginaw steering, the 2.3L engine transplant will get that rig up to highway speeds. I restored a 1950 CJ-3A with an L-head 134 in the late 'sixties, and that was an agonizing way to drive the secondary highways from San Diego to the Anza Borrego Desert. Most four-cylinder Jeep 4x4s were either flat towed (very bad on a Ross cam-and-lever steering gear!) or trailered. The '3A' eventually got towed behind our V-8 powered '55 Ford F100 pickup.

Again, welcome to the forums, looking forward to your participation. As a footnote, I also admit that our '99 XJ Cherokee Sport 4WD with 4.0L and amenities is a rather pleasant way to do the street/trail thing! With a six-inch long arm lift and air lockers at each axle, it will match a vintage CJ on the trail, too!

Thanks for the thoughts and recollections! When I was in the USAF stationed in Montana in the 70's, I belonged to the "Cascade County 4 Wheelers", and at the time, I was driving a two year old 72 Bronco. I looked at other rigs, but the wife, with one child on the ground and another on the way demanded at the very least some basic comfort items, like a roof, doors, windows, heater...There were a LOT of pre-AMC CJ's in the club back then, one I clearly remember was one that belonged to a fellow I worked with, that ended up with a 400 Pontiac, Turbo 400, and D-44 axles out of a GM pickup. That thing was an absolute monster. It was nearly as wide as it was long, but then, that was also when a 31-10.50 Tru-Trac tire was huge, and the Desert Dog's were hard to come by! I also encountered one of the first 2300 conversions I'd seen back then, in a flatfender, and it made a lot of sense to me then, and has stuck. I suppose there is a time and a place for engines that will shred differentials, I just have to admit that that time has come and gone for me. (I have to admit that I have a 69 Mustang to do that chore).I also have a small bit of news...I was out at the end of the pasture a couple days ago, checking fence, looked over at the neighbor's 'junk pile', and noticed a recent addition, a white CJ3B with what looks like an aftermarket metal roof and doors. I might have to have the wife make up some cinnamon rolls and go for a visit! If he won't sell, maybe he'd like to have my F head!

Oh, boy, not a CJ-3B! They still get my attention, in my view the most attractive 80-inch wheelbase flatfender Jeep! Though I built an 81-inch wheelbase '55 CJ-5 for my Jeep CJ Rebuilder's Manual: 1946-71, the CJ-3B would have been my preference...I opted for the more "familiar" CJ-5 look.

Light, sleek and, if you like it, and I do, a tall hood to fit an F-head or any practical swap engine, the CJ-3B was built to '64—and for good reason. In my Jeep Owner's Bible, I share a photo of a late-'fifties/early 'sixties Jeep dealership with a new CJ-3B parked alongside the CJ-5/6 models, the Willys style pickup and wagon, plus an FC, each with its following...

Oh, boy, not a CJ-3B! They still get my attention, in my view the most attractive 80-inch wheelbase flatfender Jeep! Though I built an 81-inch wheelbase '55 CJ-5 for my Jeep CJ Rebuilder's Manual: 1946-71, the CJ-3B would have been my preference...I opted for the more "familiar" CJ-5 look.

Light, sleek and, if you like it, and I do, a tall hood to fit an F-head or any practical swap engine, the CJ-3B was built to '64—and for good reason. In my Jeep Owner's Bible, I share a photo of a late-'fifties/early 'sixties Jeep dealership with a new CJ-3B parked alongside the CJ-5/6 models, the Willys style pickup and wagon, plus an FC, each with its following...